package com.liuyang.web;

//替换HttpServlet，根据请求的最后一段路劲进行方法分发

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class BaseServlet extends HttpServlet {

    //根据请求的最后一段路劲进行方法分发
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1、获取请求路径,短路径
            String uri = req.getRequestURI();
        //2、获取最后一段路径，方法名
            int index = uri.lastIndexOf("/");
            String methodName =  uri.substring(index + 1);
        //获取BrandServlet字节码文件Class
        //谁调用(继承)我，我就是this  》》》 BrandServlet继承BaseServlet
        //System.out.println(this);

        Class<? extends BaseServlet> cls = this.getClass();

        //获取方法Method对象
        try {
            Method method = cls.getMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
            //执行方法
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }

    }
}
